基质金属蛋白酶-9在多器官功能障碍综合征中的变化

Change of matrix metalloproteinase-9 in rats with multiple organ dysfunction syndrome

目的观察多器官功能障碍综合征（multiple organ dysfunction syndrome，MODS）大鼠血浆基质金属蛋白酶-9（MMP-9）的质量浓度变化以及他在大鼠肺、肾、小肠组织中的表达，初步验证细胞外基质的损伤是MODS发病机制之一，为MODS防治提供的理论依据。方法选择成年雄性wistar大鼠40只（华中科技大学医学院实验动物中心提供），随机分为正常对照组（生理盐水组，8只大鼠）、MODS模型组（32只），模型组又分为造模后12h、24h、48h、72h不同时相组，每组8只。模型制备采用二次打击模型即失血加酵母多糖攻击：大鼠左眼球取血1mL/100g，4h后无菌腹腔注射酵母多糖石蜡混悬液（1g/320mL），用量4mL/100g。造模后在不同的时相处死搜集标本。用光镜观察肺、肾、小肠标本在MODS不同时相的结构变化；用ELISA法检测对照组及模型组不同时相血浆中MMP-9的质量浓度；用免疫组化法测定MMP-9在MODS不同时相的肺、肾、小肠中的表达。计量数据以均数±标准差（x±s）表示，组间比较采用单因素方差分析，相关性采用双变量相关分析，以P〈0．05为差异具有统计学意义。结果与对照组比较，光镜下观察模型组各组均显示不同程度的脏器充血、水肿、炎症细胞浸润。ELISA检测表明造模后12-48h模型大鼠血浆中MMP-9质量浓度即显著高于正常对照组（P〈0．01），其峰值见于造模后48h（P〈0．01）；免疫组化检测表明各组织中MMP-9的阳性表达12～72h组均比正常对照组有所增加（P〈0．05），且与血浆MMP-9质量浓度变化呈显著正相关（P〈0．05）。结论MMP-9的增加与早期器官功能的损害密切相关。其机制可能是破坏血管基膜的完整性及组织结构，导致器官的损伤。

Objective To investigate the changes in the serum MMP-9 （matrix metalloproteinase-9） and the expressions of MMP-9 in lung, kidney and intestine in rats with muhiple organ dysfunction syndrome （MODS） and confirm extracellular matrix injuries being the mechanism in MODS in order to propose a novel theoretical basis for clinical treatment of MODS. Method Forty wister rats were randomly divided into two groups： control group （ n = 8） and MODS model group （ n = 32）. The rats of model group were further divided into four subgroups accordingto the time elapsed after modelling： 12 h （ n = 8）, 24 h（ n = 8） ,48 h（ n = 8） and 72 h （ n = 8）, and were modelled by celiac injection of mixed liquid of zymosan-paraffin （4 mL/100 g） after blood loss （ 1 mL/100 g） by extirpating their left eyes. Blood,lung,kidney and intestine were sampled 12,24,48 and 72 hours after models were established. The histological changes in the lung, kidney and intestine of the rats were observed by light microscope. The serum MMP-9 were measured by enzyme-linked immunosorbent assay （ELISA）. The immunohistochemistry was used to observe the expression of MMP-9 in lung, kidney and intestine during different phases of MODS. The data were processed by one-way ANOVA and Bivariate analysis. Results Compared with control group, the organs were injured by congestion, edema and inflammatory cells infiltration to a certain extent in model groups. The serum MMP-9 increased markedly 12 hours after modelling （ P 〈 0.01） and peaked 48 hours later. The expressions of MMP-9 in lung, kidney and small intestine significantly increased from 12 h to 72 h after modelling （ P 〈 0.01 or 0.05）. Conclusions The MMP-9 increased both in serum and tissue are closely associated with the pathological process of MODS. The mechanism of organ damage probably attributes to the damage of extracellular matrix and tissue construction.